Classifications

• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C4/00—Compositions for glass with special properties
  • C03C4/0007—Compositions for glass with special properties for biologically-compatible glass
  • C03C4/0021—Compositions for glass with special properties for biologically-compatible glass for dental use
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K6/00—Preparations for dentistry
  • A61K6/70—Preparations for dentistry comprising inorganic additives
  • A61K6/78—Pigments
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K6/00—Preparations for dentistry
  • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
  • A61K6/802—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics
  • A61K6/807—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics comprising magnesium oxide
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K6/00—Preparations for dentistry
  • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
  • A61K6/802—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics
  • A61K6/813—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics comprising iron oxide
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K6/00—Preparations for dentistry
  • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
  • A61K6/802—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics
  • A61K6/818—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics comprising zirconium oxide
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K6/00—Preparations for dentistry
  • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
  • A61K6/802—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics
  • A61K6/822—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics comprising rare earth metal oxides
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K6/00—Preparations for dentistry
  • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
  • A61K6/802—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics
  • A61K6/824—Preparations for artificial teeth, for filling teeth or for capping teeth comprising ceramics comprising transition metal oxides
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K6/00—Preparations for dentistry
  • A61K6/80—Preparations for artificial teeth, for filling teeth or for capping teeth
  • A61K6/831—Preparations for artificial teeth, for filling teeth or for capping teeth comprising non-metallic elements or compounds thereof, e.g. carbon
  • A61K6/833—Glass-ceramic composites
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C10/00—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
  • C03C10/0009—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing silica as main constituent
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C10/00—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition
  • C03C10/0018—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing SiO2, Al2O3 and monovalent metal oxide as main constituents
  • C03C10/0027—Devitrified glass ceramics, i.e. glass ceramics having a crystalline phase dispersed in a glassy phase and constituting at least 50% by weight of the total composition containing SiO2, Al2O3 and monovalent metal oxide as main constituents containing SiO2, Al2O3, Li2O as main constituents

Definitions

• the invention relates to sinterable lithium disilicate glass ceramics and especially those that differ due to their properties for the production of molded dental products by plastic deformation under the influence of pressure and heat.
• Lithium disilicate glass ceramics are known from the prior art.
• EP-B-536 479 describes self-glazed lithium disilicate glass ceramic articles, but these are not intended for dental applications.
• the glass ceramics are free of La 2 O 3 and are formed in a conventional manner by melting suitable starting materials, pouring them into molds and then heat treating the objects obtained.
• Lithium-silicate glass ceramics are also disclosed in EP-B-536 572. By sprinkling a finely divided colored glass on their surface, they are given structure and color, and they are used as lining elements for building purposes. They are manufactured in a conventional manner by melting suitable starting materials, shaping the melt into a desired body and heat-treating the body together with scattered colored glass. However, La 2 O 3 is not included in the glass ceramic.
• lithium disilicate glass ceramics in dental technology is also disclosed in the prior art, but these glass ceramics all contain no La 2 O 3 or MgO and only conventional methods are used for their processing into dental products, in which a heat treatment for the excretion of Crystals only on homogeneous bodies, namely monoliths formed from a glass melt, such as small glass blocks or platelets.
• a heat treatment for the excretion of Crystals only on homogeneous bodies, namely monoliths formed from a glass melt, such as small glass blocks or platelets.
• such conventional methods only allow bulk crystallization, but not surface crystallization.
• a high-strength lithium disilicate glass ceramic also describes US-A-4,189,325, this glass ceramic being required for CaO Flow improvement as well as platinum and niobium oxide for the production of contains very fine and uniform crystals.
• FR-A-2 655 264 contains lithium oxide and silicon oxide Glass ceramics for the production of dental prostheses are described, which contain very large amounts of MgO.
• US-A-5,507,981 and WO-A-95/32678 describe Lithium disilicate glass ceramics made by special processes shaped dental products can be further processed at which compress in the viscous, flowable state elevated temperatures to the desired dental product. More information on the manufacture of the used Tiles are not made. Also, the generation of Glass ceramics are handled in a conventional manner by using homogeneous Vitreous bodies, such as platelets, are heat treated. A disadvantage of these methods is that they are due to the Use of a special compressible crucible for one Dental technicians are very expensive. The glass ceramic will continue Materials heated until no more crystals in the molten material are present, otherwise the viscosity too high for pressing to the desired dental product is. Accordingly, not a glass ceramic, but a glass processed.
• the known lithium disilicate glass ceramics show shortcomings, especially when it comes to sculpting them Processing condition to shaped dental products. For Such viscosity processing is not optimal adjusted so that a controlled flow is not possible and the reaction with the investment used was undesirably high is. Furthermore, conventional glass ceramics have only a small one Temperature stability, so that made from them Dental restorations only under deformation with a sintered Glass or glass ceramic layer can be provided. Finally, there is a lack of conventional lithium disilicate glass ceramics often also in the required chemical stability for use as a dental material in the oral cavity is constantly flushed with a wide variety of fluids.
• the invention is accordingly based on the object of a lithium disilicate glass ceramic to provide the optimal one Flow behavior with little reaction with the Investment material when pressed in the plastic state into dental products shows a high temperature stability, in particular in the range of 700 to 900 ° C, and has an excellent has chemical stability.
• the invention also relates to the method for Production of shaped dental products according to claims 7 to 13, the use of the glass ceramic according to claim 14 and shaped dental products containing glass ceramic according to the Claims 15 and 16.
• the sinterable lithium disilicate glass ceramic according to the invention is characterized in that it contains the following components: component % By weight SiO 2 57.0 to 80.0 Al 2 O 3 0 to 5.0 La 2 O 3 0.1 to 6.0 MgO 0 to 5.0, especially 0.1 to 5.0 ZnO 0 to 8.0 K 2 O 0 to 13.5 Li 2 O 11.0 to 19.0 P 2 O 5 0 to 11.0 Color components 0 to 8.0 Additional components 0 to 6.0 in which (a) Al 2 O 3 + La 2 O 3 0.1 to 7.0% by weight and (b) MgO + ZnO 0.1 to 9.0% by weight make up and the color components of glass-coloring oxides (c) and / or color bodies (d) are formed in the following amounts: (c) glass coloring oxides 0 to 5.0% by weight and (d) Color bodies 0 to 5.0% by weight.
• the glass ceramic preferably consists essentially of the previously mentioned components.
• Preferred quantity ranges exist for the individual components of the lithium disilicate glass ceramic according to the invention. These can be selected independently of one another and are as follows: component % By weight SiO 2 57.0 to 75.0 Al 2 O 3 0 to 2.5 La 2 O 3 0.1 to 4.0 MgO 0.1 to 4.0 ZnO 0 to 6.0, especially 0.1 to 5.0 K 2 O 0 to 9.0, in particular 0.5 to 7.0 Li 2 O 13.0 to 19.0 P 2 O 5 0 to 8.0, in particular 0.5 to 8.0 Color components 0.05 to 6.0 Additional components 0 to 3.0.
• the glass ceramic according to the invention preferably contains color components, namely glass-coloring oxides (c) and / or color bodies (d), in order to achieve a color adaptation of a dental product made from the glass ceramic to the natural tooth material of the patient.
• the glass-coloring oxides in particular TiO 2 , CeO 2 and / or Fe 2 O 3 , merely provide a color tint, the main color being caused by the color bodies. It should be noted here that TiO 2 does not act as a nucleating agent, but in combination with the other oxides as a color component.
• the metal bodies used are customary metal oxides and in particular commercially available isochromic color bodies, such as, for example, doped spinels and / or doped ZrO 2 .
• the colored bodies can be both non-fluorescent and fluorescent materials.
• the lithium disilicate glass ceramic according to the invention can also contain additional components, for which B 2 O 3 , F, Na 2 O, ZrO 2 , BaO and / or SrO are particularly suitable.
• B 2 O 3 and F the viscosity of the residual glass phase of the glass ceramic can be influenced and it is assumed that they shift the ratio of surface to volume crystallization in favor of surface crystallization.
• the glass ceramics according to the invention are produced the method described in more detail below Manufacture of molded dental products containing Glass ceramics are used, but special shapes can be omitted.
• process step (a) an initial glass is melted, for which purpose suitable starting materials, such as carbonates, oxides and fluorides, intimately mixed together and to the specified Temperatures are heated, causing the exit glass forms. If coloring oxides are to be used, see above these are added to the batch. The addition of if necessary existing color bodies take place in a later stage of Process because its effect at high in the glass melt prevailing temperatures would be lost.
• suitable starting materials such as carbonates, oxides and fluorides
• stage (b) Poured into water and quenched into a glass granulate transformed. This procedure is common also known as fries.
• the glass granulate is then crushed in step (c) and in particular with conventional mills to the desired grain size ground.
• an average grain size of the obtained Powder of 10 to 50 microns, based on the number of particles, preferred.
• step (d) the addition of any that are present is then carried out Color bodies.
• step (e) the powder is then compacted into a glass blank of the desired geometry and heterogeneous structure, with pressures of in particular 500 to 2,000 bar being used and in particular being carried out at room temperature.
• This process step of pressing into a blank with a heterogeneous structure is important so that, in contrast to the methods known from the prior art, in the subsequent heat treatment in step (f), surface crystallization can also take place in addition to volume crystallization.
• the heterogeneous structure of the starting glass blank consisting of compressed starting glass powder particles enables controlled surface crystallization on the inner surfaces of the glass powder.
• the heat treatment in stage (f) is used for triggering the crystallization of the starting glass blank and thus for Formation of the glass ceramic after the completion of this process step is a densely sintered glass ceramic blank.
• This Blank usually has the shape of a small cylinder or a small tile.
• step (g1) the present as a blank Dental product at a temperature of 700 to 1200 ° C and through Application of pressure from 2 to 10 bar to a dental product desired geometry plastically deformed.
• a blank Dental product at a temperature of 700 to 1200 ° C and through Application of pressure from 2 to 10 bar to a dental product desired geometry plastically deformed.
• the press furnace used for this is the Empress® furnace from Ivoclar AG, Liechtenstein.
• the dental product in the form of a blank has a viscosity of 10 5 to 10 6 Pa ⁇ s during plastic deformation in stage (g1).
• the dental product present as a blank can also be used in Step (g2) mechanically desired to a dental product Geometry are processed, especially computer-aided Milling machines are used.
• the dental product of the desired geometry obtained after step (g1) or (g2) is provided with a coating in step (h).
• a ceramic, a sintered ceramic, a glass ceramic, a glass, a glaze and / or a composite are particularly suitable as coatings.
• Coatings which have a sintering temperature of 650 to 950 ° C. and a linear coefficient of thermal expansion which is smaller than that of the dental product to be coated are advantageous. Coatings whose linear thermal expansion coefficients do not deviate from those of the substrate by more than ⁇ 3.0 ⁇ 10 -6 K -1 are particularly advantageous.
• a coating is applied in particular by sintering, for example a glass, a glass ceramic or a composite.
• sintering for example a glass, a glass ceramic or a composite.
• the dental product containing lithium disilicate glass ceramic is brought into a temperature range which lies above the transformation point of the residual glass matrix of the glass ceramic.
• Conventional lithium disilicate glass ceramics are often undesirably deformed because they have too little temperature stability.
• the dental product according to the invention has an excellent temperature stability, for which in particular the content of La 2 O 3 and Al 2 O 3 in the stated amounts is responsible.
• the glass ceramic according to the invention also has very good chemical resistance, which is caused by the use of Al 2 O 3 , La 2 O 3 , MgO and ZnO in the amounts specified.
• Shaped dental products according to the invention that have a content have on the glass ceramic according to the invention come in particular Dental restorations, such as an inlay Onlay, a bridge, a pen structure, a facing, shells, Veneers, facets, connectors, a crown or a partial crown, in Question.
• Dental restorations such as an inlay Onlay, a bridge, a pen structure, a facing, shells, Veneers, facets, connectors, a crown or a partial crown, in Question.
• This example describes the preparation of an inventive Glass ceramics and their use as scaffolding material for the production of an individually formable all-ceramic Product, e.g. a crown or a multi-unit bridge, on which in addition a customized dental sintered ceramic is burned up.
• an individually formable all-ceramic Product e.g. a crown or a multi-unit bridge
• a starting glass with the chemical composition given in Table I, Example 21, was produced.
• a mixture of oxides, carbonates and phosphates was melted in a platinum / rhodium crucible at a temperature of 1500 to 1600 ° C during a homogenization time of one hour.
• the glass melt was quenched in water, and the glass frit formed was dried and ground to an average grain size of 20 to 30 ⁇ m.
• glass-coloring oxides namely CeO 2 , TiO 2 and Fe 2 O 3 , made it possible to dispense with coloring using colored bodies.
• the colored glass powder was then removed using a uniaxial dry press at room temperature and at one Pressing pressure of 750 bar to cylindrical starting glass blanks, in hereinafter referred to as green compacts, with a mass of approx. 4 g pressed.
• the green compacts were removed in a kiln under vacuum sintered glass ceramic according to the invention in the form of a blank.
• the green compact was at 500 ° C for pre-burned an hour.
• the blank was then densely sintered in a second sintering treatment at 850 ° C for 2 hours, with a heating rate of 30 ° C / min. was worked.
• the blanks obtained had comparable optical properties, e.g. Translucency, staining and turbidity as usual dental ceramic sales products such as IPS Empress OI Blanks from IVOCLAR AG, Liechtenstein.
• Sintered blanks were used to determine the biaxial strength in slices with a diameter of 12 mm and a thickness of 1.1 mm sawn.
• the biaxial strength was determined with a test apparatus with three-point support (steel balls with a Diameter of 3.2 mm) with selective application of force via a stamp with a diameter of 1.6 mm according to ISO 6872-1995 E "Dental Ceramic".
• the feed rate of the Load application was 0.5 mm / min.
• the under these conditions determined biaxial strength was 261 ⁇ 31 MPa.
• the glass-ceramic blanks obtained were finally pressed in the viscous state into the sample geometry desired for the respective test using the pressing method and pressing furnace according to EP-A-0 231 773.
• the standby temperature of the press furnace was 700 ° C, the heating rate up to the press temperature 60 ° C / min., The press temperature 920 ° C, the holding time at the press temperature 10 min. and the pressure 5 bar.
• the mold was cooled in air and the test specimens were removed from the mold by sandblasting with Al 2 O 3 powder and glass beads.
• the samples obtained had the following properties:
• the plastically deformed glass ceramic had translucent properties, which enable the dental technician to make full ceramics out of it Dental products such as Crowns or multi-unit To create bridges that visually meet the requirements of a natural one Tooth.
• Dental products such as Crowns or multi-unit To create bridges that visually meet the requirements of a natural one Tooth.
• the hot-pressed glass ceramic was tooth-colored in the base glass. The color intensity could thereby by the concentration of the coloring oxides or through the additional use of colored bodies be set specifically.
• rods measuring 1.5 ⁇ 4.8 ⁇ 20 mm 3 were pressed, and these were ground on all sides with SiC wet abrasive paper (grain size 1000).
• the bending strength was determined with a span of the test equipment of 15 mm and a feed speed of the load application of 0.5 mm / min. according to ISO 6872-1995 E "Dental ceramic".
• the 3-point bending strength determined under these conditions was 341 ⁇ 98 MPa.
• cylindrical samples with a diameter of 6 mm were used and a length of 20 mm.
• the in the temperature range of Expansion coefficient determined for these samples at 100 to 500 ° C was 10.6 ⁇ m / mK.
• rods measuring 1.5 ⁇ 4.8 ⁇ 20 mm 3 were pressed, and these were ground on all sides with SiC wet abrasive paper (grain size 1000).
• the samples were notched on one side to a depth of 2.8 mm using a diamond cutting disc (0.1 mm thickness) and then examined for their 3-point bending strength.
• the bending strength was determined with a span of the test equipment of 15 mm and a feed speed of the load application of 0.5 mm / min.
• the K 1c value determined was 4.0 ⁇ 0.2 MPa ⁇ m.
• This example describes the preparation of an inventive Glass ceramics and their use as scaffolding material for the production of an individually formable all-ceramic Product, such as a crown or a multi-unit bridge, on which in addition a customized dental sintered ceramic is burned up.
• a starting glass with the one in Table I, Example 18, chemical composition specified To was a mixture of oxides, carbonates and phosphates in one Platinum / rhodium crucible at a temperature of 1500 to 1600 ° C melted during a homogenization time of one hour. The glass melt was quenched in water, and the one formed Glass frit was dried and to an average grain size of Ground 20 to 30 ⁇ m. The glass powder was made with commercially available Color bodies and fluorescent agents are added and homogenized.
• the colored glass powder was then removed using a uniaxial dry press at room temperature and at one Press pressure of 750 bar to form cylindrical green compacts with a mass of about 4 g pressed.
• the green compacts were placed in a kiln under vacuum to the glass ceramic according to the invention in the form of a Sintered blanks.
• the green compact was added Pre-baked at 500 ° C for 20 minutes.
• the blank is then subjected to a second sintering treatment at 850 ° C for 30 minutes, with a heating rate of 30 ° C / min. was worked.
• the blank is like proceeded in Example 22.
• the blanks obtained had comparable optical properties, such as translucency, staining and turbidity, as usual dental ceramic sales products, e.g. IPS Empress Dentin 24 Blanks from IVOCLAR AG, Liechtenstein.
• the biaxial strength was 270 ⁇ 38 MPa.
• the glass-ceramic blanks obtained were finally pressed in the viscous state into the sample geometry desired for the respective test using the pressing method and pressing furnace according to EP-A-0 231 773.
• the standby temperature of the press furnace was 700 ° C, the heating rate up to the press temperature 60 ° C / min., The press temperature 920 ° C, the holding time at the press temperature 10 min. and the pressure 5 bar.
• the mold was cooled in air and the test specimens were removed from the mold by sandblasting with Al 2 O 3 powder and glass beads.
• the plastically deformed glass ceramic had translucent properties, which enable the dental technician to make all-ceramic out of it Dental products such as Crowns or multi-unit To create bridges that visually meet the requirements of a natural one Tooth.
• Dental products such as Crowns or multi-unit To create bridges that visually meet the requirements of a natural one Tooth.
• the 3-point bending strength was 347 ⁇ 37 MPa.
• the coefficient of expansion determined in the temperature range from 100 to 500 ° C was 10.7 ⁇ m / mK.
• the K 1c value determined was 3.8 ⁇ 0.5 MPa ⁇ m.
• the area-related mass loss determined according to ISO 6872-1995 after 16 hours' storage in 4% by volume aqueous acetic acid solution was significantly below the standard value for dental ceramic materials of 2000 ⁇ g / cm 2 .

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• Health & Medical Sciences (AREA)
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• Oral & Maxillofacial Surgery (AREA)
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• Ceramic Engineering (AREA)
• Epidemiology (AREA)
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• Plastic & Reconstructive Surgery (AREA)
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• Inorganic Chemistry (AREA)
• Molecular Biology (AREA)
• Glass Compositions (AREA)
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• 1997
  • 1997-08-15 EP EP97250239A patent/EP0827941B1/fr not_active Expired - Lifetime
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